Railway-traffic-controlling apparatus



2 Sheets-Sheet 1 IINVENTOR I a Ma,

BY Z

H. o. HOLTE RAILWAY TRAFFIC CONTROLLING APPARATUS Filed Sept. 9, 1924 June 29 1926.,-

M1 ATTORNEY June 29 1926.

H. O. HOLTE RAILWAY TRAFFIC (EONTROLLING APPARATUS 2 Sheets-Sheet 2 Filed Sept. 9, 1924 Y QJZ M H ATTORNEY Patented June 29, 1926.

UNITED STATES 1,590,825 PATENT OFFICE.

HAROLD -O. HOLTE, OF WILKINSBURG, PENNSYLVANIA, ASSIGNOR TO THE UNION SWITCH &'SIGN.AL COMPANY, OF SWISSVALE, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

RAILWAY-TBAFFIC-CONTROLLING APPARATUS.

Application filed. September 9, 1924. Serial No. 736,688.

My invention relates to railway traffic controlling apparatus, and also to relays suitable for use therein. More specifically my present invention relates to apparatus of the type wherein governing means on a car or train is controlled by energy received from the trackway.

I will describe two forms of apparatus and two forms of relays all embodying my invention, and will then point out the novel features thereof in claims.

In the accompanying drawings, Fig. 1 is a diagrammatic view showing one form of traffic controlling apparatus embodying my 1 invention. Fig. 2 is a diagrammatic view showing a modification of a portion of the apparatus shown in Fig. 1.. Fig. 3 is a sectional view showing one form of relay embodying my invention. Fig. i is a view showing in side elevation the relay shown in Fig. 1. Fig. 5 is an end view of the rotor member 24 of the relay shown in Figs. 3

and 4.

Similar reference characters refer to similar parts in each of the several views. I

Referring first to Fig. 1, the reference characters 1 and 1 designate the track rails of a railway along which traflic normally moves in the direction indicated by the arrow. These rails are divided by insulated joints 2 to form track sections A-B, B-C,

etc. Each track section is provided with a track circuit comprising a battery connected across the rails at the exit end of the section and designated by the reference character E,

with an exponent corresponding to the location. Each track circuit also comprises a track relay connected across the rails ad acent the entrance end of the section and designated by the reference character I), with an exponent corresponding to the location.

Each track battery E is connected with the rails through the secondary of an adjacent transformer designated "by the reference character F, with an exponent'corresponding to the location. The primary of each transformer F is at times supplied with traingovern-ing current from the secondary 27 of an adjacent transformer designated by the 50 reference character H, with an exponent corresponding to the location, this supply being controlled by a contact 29 of track relay D for the section next in advance. The primary 28 of each line transformer H is connected with a transmission line J which is constantly supplied with alternating current by a generator K.

It will be seen from the foregoing that when a given section, such as B-C is unoccupied, train-governing current will be supplied to the track rails of section AB, because contact 29 of track relay D is closed; whereas, when section BC is occupied by a car or train, the'supply of train-govern lng current to the rails of section AB will be discontinued because contact 29 of track relay D is open.

Located adjacent the entrance end of each track section is a roadside signal designated by the reference character G, with an exponent corresponding to the location. These signals form no part of my present invention. and consequently, the means for controlling them is omitted from the drawing.

Section A-B is occupied by a car or, train represented by a pair of wheels and axle V. Mounted in front of the forward wheels of this train are two pick-up windings 3 and 3 located in inductive relation with respect to the two track rails 1 and 1 It will be seen, therefore, that when the train V is in a track section which is supplied with alternating train governing current, voltages will be induced in the pick-up windings 3 and 3 which voltages will have the same frequency as the train-governing current in the track rails. The pick-up. windings 3 and 3 are connected in series in such manner that the voltages induced in these windings by traingoverning current in the track rails are additive, and these windings are, furthermore, connected in series with awinding 5 of a relay L. The circuit including the windings 3 and 3*- and the relay winding 5 is preferably tuned to resonance at the frequency of the train governing current by a condenser 4.

The relay L comprises a core 7 of magnetizable material, preferably U-shaped, as shown in'the.draw ing, and afixed member 9 also of magnetizable material located between the pole pieces of the core 7. The winding 5 is located between the member 9 .and the pole pieces of the core 7, and. is

mounted to oscillate about an axis which is perpendicular to the plane. of the drawing. Attached to the winding 5 is a contact member 8, which co-operates with a fixed contact.

member 8 for the control oftrain-governing apparatus,'as will be hereinafter explained. The core 7 of relay L is provided with a winding 6, which is sup lied withcurrent by a tuning fork oscillator T, the

frequency of the current supplied by oscillatorT being different from the frequency of the train-governing current. The oscillator' T comprises a tuning fork which serves to interrupt the supply of current from a battery 13 to the primary winding 11, and the circuit including this primary winding is preferably ,tuned by a condenser 12 to resoname at the frequency of the current delivered by oscillator T.

I will assume that the frequency of the train-governing current in the track rails is 150 cycles per second, and that the frequency supplied to winding 6 of relay L is 200 cycles per second The movable coil 5 will then have two sinusoidal vibromotive forces acting upon it. One of these forces will have a frequency equal to the difference 1 of the two frequencies impressed on windings 5 and 6, while the other of these forces will have a frequency equal to the sum of the. two frequencies impressed on windings 5 and 6. The vibromotive force is proportional to the strength of the currentslin the two relay windings, and so the relay may be made more sensitive by increasing the V strength of the current supplied to winding 6 by the tuning fork oscillator T. If the winding 5 and contact member'8, which I will term the vibrating member of the relay, are mechanically tuned to one of the vibromotive forces, the response of this member will be considerable. Since with a given vibromotive force the displacement of the vibrating member is inversely proportional to the frequency, it is preferable to mechanically tune the vibrating member, by suitable means such as a slidable weight 8", to the diflerence of the two impressed fre- .quencies.

The contact 88 of relay L controls a circuit which includes a battery 14 and the primary 15 of a transformer N, so that when relay L is operating, pulsating direct current is supplied to the primary 15 and alternating current is delivered by the secondary 16 of transformer -N. This alternating current, as here shown, is supplied to a rectifier P, which in'turn supphes unidirectional current to a relay Q having a contact 17 which controls two train-governing lamps G and B. When relay L is operating, front contact 1718 of relay Q is closed, so that lamp G is 1i hted and the As is well understood, the higher the frequency of the train governing current in the track rails, the greater the amount of power which can be picked up by the traincarried windings 3 and 3. It is also well understood that in a vibrating relay, the

lower the frequency to which the vibrating member is tuned, the greater will be the amplitiide of the motion of this member. By means of the apparatus shown in Fig. 1, I am able to combine the advantage of the increased power picked up at the higher frequencies with the reater amplitude available in a low frequency vibration relay. This relatively great amplitude makes the adjustment and operation of the vibrating member more satisfactory than when the amplitude is relatively small.

If the frequency of the train-governing current varies from the proper value, the current in the moving coil 5 of relay L will decrease, and the vibrating member of this relay is no longer in mechanical resonance at the difference frequency. Both of these effects decrease the amplitude of vibration of the vibrating member, and so the selectivity may be made exceedingly sharp. Assuming the frequencies mentioned above, if the frequency of the traingoverning current changes to 151.5 cycles, whch is 1% above the normal frequency, the

difference frequency elfective in the relay L will then be 48.5 c cles, which is 3.3% below the resonance requency of the" vibrating member. Furthermore, the vibrating member may be constructed to have a very low decrement.

It is to be noted that with the frequencies referred to above, a fre uency of 250 cycles in the track will also give a difference frequency of 50 cycles. Electrical tuning of the pick-up circuit, however, will prevent operation of the relay L on any amount of such higher. frequency which would ordinarily be present in the track rails.

Referring now to Fig. 2, a rectifier P is interposed between the pick-up windings 3, 3 and the movable winding 5 of relay L, so that this movable winding is supplied withunidirectional current. The movable member will then be tuned to mechanical resonance at the frequency of the current supplied to winding 6 by the tuning fork oscillator T of Fig. 1. With the modified apparatus shown in Fig. 2, the frequency of the vibromotive force is not dependent on the frequency of the current picked up by windings 3 and 3 from thetrack rails.

Referring now to Figs. 3, 4 and 5, the vibration relay here illustrated is of the induction motor type, comprising a stator 20,

preferably of laminated iron, provided with four pole pieces 21, 21", 22, and 22. More vided with a winding 5, whereas pole pieces 22 and 22 are provided with a winding 6, which windings may be supplied with currents in the manners shown in Fig. 1. These windings act on a rotor 24, which, as here shown, is of the shell type and is mounted for rotational vibration on two torsion strips 25 and 25*, which strips are in turn supported in frameworks 26 and 26 attached to the stator member 20. Preferably a stationary iron core 23 is located inside of the rotor 24.

If alternating currents of different frequencies are supplied to the two windings 5 and 6, they will produce a torque on the rotor 24, which torque will undergo a cyclic variation in direction at the difference between the frequencies of thetwo impressed I currents. If the rotor 24 is mechanically tuned to this difference frequency it will oscillate. The rotor may be employed to operate a circuit controller in any desired manner, this circuit controller, as here shown, being a contact member 8 fixed to the rotor and co-operating with a fixed contact member 8%, When the rotor is at rest,

this contact is open, but when the rotor is oscillating, the contact is perdiodically closed.

The induction motor relay L, shown in Figs. 3, 4 and 5, may be employed in'the apparatus shown in Figs. 1 and.2, in place of the moving winding relays shown in 7 those views. The induction motor type of relay offers the advantages of light-weight moving parts and low air friction losses In any event, a relay with no moving iron is preferable, because it will not respond to the frequency of the current generated on the trkain no matter how strong such current ma e.

lthough I have herein shown and described only a few forms of a paratus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what claim is 1. Railway traffic controlling apparatus comprising a train-carried relay having two windings, means located in the trackway for lcausing current of one frequency to be supplied to one of said windings, means located on the train for supplying current of a different frequency to the other of said windings, said relay having a movable member tuned to the frequency of one of the vibromotive forces due to the joint action thereon of said two currents, and governing comprising. a train-carried relay having a fixed. winding and a movable winding, means located in the trackway for causing current of one frequency to be supplied to one of said windings, means located on the train for supplying current of a diflerent frequency to the other of said windings, said movable member being tuned. to the frequency equal to the difference between the frequencies of the two currents supplied to said windings, and governing apparatus on the train controlled by said relay.

4, Railway traflic controlling apparatus comprisinga train-carried relay having two windings, means located in the trackway for causing current of one frequency to be supplied to one of said windings, means located on the train for supplying current of a different frequency t9 the other of said windings, said relay having a movable member which is subjected to the vibromotive forces due to the joint action of said two currents and is tuned to the frequency of one of said vibromotive forces, and governing apparatus on said train controlled by said' movable member.

5. Railway traffic controlling apparatus comprising a train-carried relay having two windings, meanslocated in the trackway for causing current of one frequency to be supplied to one of said windings, means located on the train for supplying current of a different frequency to the other of said windings, said relay having a movable member which is subjected to the vibromotive forces due to the joint action of said two currents and is tuned to they frequency equal to the difference between the frequencies of said two current-s, and governing apparatus on the train controlled by said movable member.

6. Railway traffic controlling apparatus comprising a train-cai'ried relay having two windings, means controlled from the trackway for causing uni-directional current to be supplied to one of said windings, means located on the train for supplying alternating current to the other of. said windings, said relay having a movable member subjected to the joint action of said two currents and tuned to the frequency of said alternating current, and governing apparatus on the train controlled by said movable member.

7. Railway trafiic controlling apparatus comprising a train-carried relay comprising a stator having two windings, trackway means for causing current of one frequency to be supplied to one of said windings, means on the train for supplying current of another frequency to the other of said windings, said relay also comprising a rotor mounted for rotational Vbiration and tuned to the difierence between the frequencies of said currents, and governing apparatus on the train controlled by said relay.

8. Railway traflic controlling apparatus comprising means located in the trackway for supplying current of one frequency 'to trains, means located on a train for supplying current of another frequency, a device located on said train and responsive to the joint action of said two currents but not to either current alone, and governing apparatus on the train controlled by said device.

9. Railway traflic controlling apparatus comprising means located in the trackway for supplying current of one frequency to trains, means located on a train for supplying current of another frequency, and govcrning apparatus on said train responsive to the joint action of said two currents'but not responsive to either of said currents alone.

In testimony whereof I aflix my signature,

HAROLD O. HOLTE. 

